Epstein-Barr viral (EBV) infection is the second most frequent and important viral infection in pediatric liver transplant recipients with cumulative rates for post-transplant lymphoproliferative disease (PTLD) as high as 20% under cyclosporine-based immunosuppression. Therapeutic approaches to EBV infection after transplantation include reduction or withdrawal of immunosuppression. Infection with EBV prior to transplantation appears to provide protection against symptomatic EBV infection after transplantation (including PTLD). In the absence of an effective vaccine, preventive strategies such as passive immunizaiton with intravenous immunoglobulin (IVIG) may provide protection against severe EBV disease. Cytogam is a pooled IVIG product which, when demonstrated, showed 10 to 100 fold greater anti-EBV antibody titers compared to standard IVIG. Accordingly, this product is a reasonable candidate to determine whether passive prophylaxis can result in a decreased frequency and severity of EBV infection after pediatric liver transplantation.